Keratin-based particles for protection and restoration of hair properties

Human hair is an element with unquestionable relevance in society both for women and men. Therefore, it is of great importance to develop new cosmetic products for hair care capable to restore and improve hair's characteristics. Here, we explore the potential of keratin-based particles in the protection and recovery of hair mechanical properties and thermal stability.

Keratin-based particles were obtained by high pressure homogenization (HPH) using keratin and silk fibroin. The particles were characterized regarding size, superficial charge and polydispersity index. Their safety to cells was assessed using human skin keratinocytes. Virgin and overbleached Asian hair were treated with eight keratin-based formulations. The effect of particles on hair's mechanical properties was evaluated in terms of stiffness and tensile strength. The impact of treatments in hair thermal performance was studied using differential scanning calorimetry (DSC).

Keratin-based particles were capable to recover and/or improve the mechanical properties of virgin and overbleached hair. Virgin hair treated with K₈₀ SF₂₀ P particles presented an improvement in the mechanical properties of around 40%. An increase in keratin α-helix denaturation enthalpy and in surface smoothness for both types of hair was also verified after treatment. These particles demonstrated stability over time and proved to be safe when tested in human keratinocytes.

The keratin-based particles here presented have the potential to be incorporated in the development of new and effective hair care cosmetic formulations.